Wrench



Feb. 12, 1946., F. H. ROHR 2,394,808

' WRENCH Filed Feb. 9, 1944 2 Sheets-Sheet 1 IN VEN TOR BY FREDERICK H. ROHR AT TOHNE Y Patented Feb. 12, 1946 A I I 2,394,808

WRENCH Frederick H. Bohr, San Diego, Calif, assignor to Rohr Aircraft Corporation, Chula Vista, Caliifi,

a corporation of California Application February 9, 1944, Serial N 0. 521,688 a 3 Claims.

My invention relates to wrenches, particularly cranking bars employed for turning the shafts of engines or motors, and its objects are to permit great force to be applied to the object to be turned, with minimum wear thereon and without injury thereto; to lighten the construction of the jaws and handles of the wrench without impairing the strength thereof; and to allow the ready repair, replacement and assembly of the several parts. These and other important objects will appear from the drawings and as here inafter set forth and described.

This application, insofar as this invention is concerned, includes most or substantially all of the disclosure as to said wrench presented in my earlier copending application Serial No. 487,862, filed May 21, 1943, and entitled Tilting arcs,

issued May 9, 1944, as U, S, Patent No. 2,348,309.

Reference may be had to said copending application for details of construction which form no part of the present invention except as herein disclosed and claimed.

Attention is hereby directed to the drawings illustrating a preferred form of m invention in which similar numerals of designation refer to.

similar parts throughout the several views and in which- Figure 1 is a side elevation of my improved wrench, the enclosed parts thereof being shown in dotted lines, and the handles thereof being shown broken, for purpose of better illustration;

Fig. 2 is an end elevation of said wrench, showing its application to the shaft of a motor, with the jaw of the wrench in engagement with the splined grooves of said shaft;

Fig. 3 is an enlarged view of the yoke and adjacent parts of the wrench shown in Fig. 1, showing the jaw detached therefrom;

Fig. 4 is a front elevation of the jaw shown in Fig. 3;

Fig. 5 is a plan view and 5a is a side elevation of one of the pair of the securing plates used for fastening the jaw in the hollow of the yoke;

Fig. 6 is a plan view and 6a is a side elevation of one of the pairof cap screws used for attaching said plates to said yoke, and

Fig. '7 is a plan and la is a side elevation of one of the pair of dowels employed to position said plates upon said yoke.

Referring to the drawings-my improved wrench is there shown in the form of the cranking bar 8, comprising the curved yoke 9, the jaw in detachably secured thereto, and hollow handles ll removably affixed to the extensions l2 of said yoke; all of said parts being hard metal and of sturdy construction, except that the jaw I 0 is preferably of softer metal, such as zinc, lead, brass, aluminum or similar material. As shown, the said law it is curved to fit the hollow of said yoke and is positioned therein by means of the dowel pin 25, the ends of which are shaped to engage with recesses I3 and 14 respectively in the walls of said yoke and insert. It is fastened to said yoke by cap screws [5, the shanks of which passing through openings 15a provided therefor in a pair of securing plates I6, engage with threaded openings ll in the ends of said jaw; the said plates extending over the ends of both said yoke and jaw and serving firmly to connect the same. As a further means of preventing dislodgement of said jaw from the hollow of said yoke, I prefer to use a pair of dowels [8, which, engaging with openings l9 in said securing plates and openings 29 in the ends of said jaw, serve to prevent lateral displacement thereof and to secure the same more firmly in position.

The yoke 9, while sturdy. in character, is preferably lightened in weight by having openings 2 la and 2 lb made therein in such manner as not materially to diminish the strength thereof. To each end of said yoke is welded a hollow metallic extension l2, shaped to engage with the bore of one of the hollow handles H, and afiixed thereto by pins 22 and 23 extending through the walls thereof. The said handles, if desired, could be made solid, with sockets provided to receive the ends of extensions [2, but preferably are made hollow to secure lightness of construction, without loss of strength and for ease in handling are each made with a slight bend as shown in the drawings. The jaw I0 is provided with the teeth 24 shaped to engage with the usual splined area. 25 encircling a conventional motor shaft 26, such as shown in the conventional form of motor 21 shown in Fig. 2. As is obvious, the form and arrangement of the teeth 24, or contact surface of the jaw ID, may be modified to suit the form and arrangement of the splines or grooves on the motor shaft, or to suit the application of the wrench to the object to be turned.

To install my improved wrench 8 in operative position, it is necessary first to engage the opening of the jaw It with the smooth reduced portion 28 of the shaft 26 immediately adjacent to the splined area 25 (see Fig. 2) and then by moving said jaw longitudinally toward the motor 21 to interlock the teeth 24 with the grooves of the splined area 25, at which time the workman, by grasping handles I I, can rotate the said shaft '26 to the degree desired. To remove said wrench 8 out of engagement with said shaft 26, this operation obviously may be accomplished by sliding the wrench outwardly and off said splines, and.

. by lifting the wrench out of position. By reason mold or die and being easily replaceable.

While I have described my improved wrench with particular reference to its use as a cranking bar for turning the shafts of motors or other engines, I do not desire so to limit its scope of use, since as is obvious such wrench could be applied to other objects to be turned by conforming the shape of the jaw so that proper engagement could be made with such objects. By rea. son of the fact that such jaw is replaceable,'its contacting surface could be made in a variety of forms so as to permit it being employed extensively in the art inmany instances where the turning action of a wrenchwas required. Being usually made of softer metal than that heretofore employed, and readily replaced, the life of the wrench is greatly extended, and at the same time the wear upon the object to be turned is greatly reduced from wear heretofore necessarily experienced in the use of wrenches commonly used in the art. Also through the use of the soft metal jaw, much greater turning force can be applied to the work, without injury, than has been the'case where hard metals have been used.

My invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The, present embodiment, as above set forth, is therefore to be considered in all respects as illustrative and not restrictive, thescope of my invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of'equivalency of the claims are therefore intended to be embraced therein;

What I claim and desire to secure by Letters Patent is:

1. In a cranking bar for turninga splined motor shaft, the combination of a hard metallic yoke having a hollow therein, handles fastened to the ends of said yokefa replaceable jaw of soft metal seated within the hollow of said yoke and provided with teeth shaped to register and to make engaging contact with the splines of said shaft, attachment plates and means associated therewith for removably securing the ends of said jaw to the ends of said yoke and while so secured of preventing both lateral and longitudinal movement of said jaw within said yoke.

2. In a cranking bar for turning a splined motor shaft, the combination of a hard metallic yoke having a curved hollow therein, a pair of bent hollow handles removably fastened to the ends of said yoke, a replaceable jaw of soft metal formed to fit and to be seated within the hollow of said yoke and provided with teeth shaped to register and to make engaging contact with the splines of said shaft, a pair of attachment plates and means associated therewith for removably securing the ends of said jaw to the ends of said yoke and while so secured of preventing both lateral and longitudinal movement of said jaw within said yoke.

3; In a cranking bar for turning a splined motor shaft, the combination of a hard metallic yoke having a curved hollow therein, a pair of bent hollow handles removabl-y fastened to the. ends of said yoke, a replaceable jaw of soft metal formed to fit and to be seated within the hollow of said yoke and provided with teeth shaped to register and to make engaging contact with the splines of said shaft, and a pair of removable attachment plates secured by cap screws to the ends of said jaw and prevented from longitudinal and lateral movement by dowel pins engaging both said jaw and plates.

- FREDERICK H. ROHR. 

